A Caltrans spokesman said Sunday that "it's not going to be an easy day" for Monday morning rush-hour commuters into Los Angeles after a tanker truck flipped and spilled 8,500 gallons of gasoline on the 5 and 2 freeway connector roads near Dodger Stadium on Saturday, closing those roads indefinitely until an examination and repairs of the roadways are completed.

"We are urging people to take public transportation Monday, and consider taking the Metrolink trains," said Patrick Chandler, a spokesman for Caltrans, at an afternoon news conference.

The closures include the southbound 2 to the southbound 5 and the northbound 2 to the northbound 5 connector roads and at least two lanes of the southbound 5.

All northbound 5 lanes will be closed this morning near the stadium.

When completed, the repairs should allow the 5 Freeway to reopen its two closed southbound lanes and the four northbound lanes. Those have been closed since the fire on Saturday.

Caltrans said hundreds of thousands of cars a day use the 5 to get into Los Angeles or travel farther south or east.

Many commuters from the San Gabriel Valley and the Inland Empire use the westbound 210 Freeway and the southbound 2 Freeway to reach L.A. instead of the 10 Freeway, which normally is heavily congested in the mornings. An alternative route would be to take the 605 Freeway to either the 10 or 60 freeways into L.A.

On Sunday, northbound traffic was detoured off the 5 to the two-lane ramp to the northbound 2. That route takes drivers through Glendale and back to the 5 via either the 134 or 210 freeways.

Traffic was diverted onto surface streets and was reported to be heavy on neighborhood streets.

The California Highway Patrol said Sunday it hadn't determined the cause of the crash that dumped 8,500 gallons of burning gasoline into the L.A. River or storm drains, Los Angeles Fire Department spokesman Brian Humphrey said.

Humphrey said state and federal officials were trying to assess damage to the river and area.

"We don't have a quantity of what went into the river, but it was sizeable," Humphrey said.

Portions of the L.A. River in this area just re-opened to the public for kayaking, fishing, and other activities. Additionally, nonprofit river groups held a large cleanup effort for the river two months ago.

"It's just awful to hear," Rick Rabins, president of The Village Gardeners, a nonprofit group dedicated to beautifying the L.A. River, said when told of the accident. "Toxic contamination is a pretty terrifying thing."

The fire also ignited brush near the freeway.

Fire officials on Saturday warned of possible public hazards near manhole covers and storm drains in the area because of explosive runoff, which could cause flames to erupt from the underground passages.

Silver Lake resident Geoff Reyes said he was working in his yard when he heard loud blasts from the site of the accident, about 300 yards away.

After seeing smoke rise, he and many neighbors walked closer to the fire to get a better look before they heard two or three loud pops.

"It was kinda weird because the fire had been going on for a while and we thought there were no more explosions left," Reyes said.

Not long after, Reyes, his wife and two kids left their house to avoid inhaling foul fumes and were surprised to find police had blocked off their street with yellow tape -- even though his neighbors hadn't been evacuated.

Police said the popping noises were manhole covers popping off, and warned him to stay away from them, Reyes said.

Reyes said he and his family were told they could leave, but couldn't come back until the area was deemed safe.

Staff Writer Dakota Smith and the Associated Press contributed to this report.